[Early ultrastructural findings on lymph node sinuses].

Abstract

Submandibular and mesenteric lymph nodes of Chiroptera (Rinolophus f.e. and Pipistrellus p.) display a marginal sinus, located between the capsule and the cortical parenchima. There are also trabecular sinuses, which deepen in both the cortical and paracortical zones and medullary sinuses in the zona medullary. All the above mentioned sinuses are made up of a distinct endothelial cell wall lying on a variably thick layer of amorphous substance and collagen fibers. Moreover, the endothelial subcapsular wall of the marginal sinus and the endothelium lying the connective tissue septa form a continuous layer, whereas the endothelium adjacent to the parenchima in the marginal, trabecular and medullary sinuses exhibits and interrupted course, so as to allow a free to and from passage of cells between the parenchimal and sinus compartments. The Authors also compare the ultrastructural features of the lymph node sinuses in Chiroptera with those of other mammals including man.